Default/Custom Error page not displaying

I am looking at the docs here - Default Auth0 Error Page

If your callback URL is valid, when an authorization error occurs, the Authorization Server returns the appropriate error and state parameters to your callback URL.

I have added a url to “Allowed Callback Urls” in my application settings, I have also tried both the Default/Custom Error page options in Tenant Settings.

I still receive a black error page when viewing an expired link. All other topics I have come across on the community board remain unresolved. I am working on an inherited implementation for a Next.js web app.